Friction application device

ABSTRACT

A friction application device includes an application element which defines a rotational axis and which is movable by a moving device on a surface of a workpiece and in a relative movement with respect to the surface of the workpiece. At least one supporting tool is non-coaxial with the rotational axis and has an arcuate outer periphery in direct contact with the application element.

BACKGROUND OF THE INVENTION

It is known from the prior art that a material is applied to a surfaceof a workpiece by means of an application element. This is done by wayof a relative movement of the application element relative to thesurface of the workpiece. The contact region of the application isplasticized either by way of preheating by means of external heatsources or by friction heat, so that material can be applied. DE 10 2008044 763 describes a method of such a kind.

Both in the case of cylindrical or rod-shaped application elements whichare rotated about their longitudinal axis, and in the case ofcylindrical roll-like application elements which are rotatable about anaxis arranged perpendicular to the contact plane, a deformation withbead formation is observed with a progressing material application,especially in the case of application elements consisting of metallicmaterials. This process takes place in the case of friction applicationwelding and also in the case of friction coating.

The bead formation has the effect that less material is available forthe application process or coating process proper. Thus, the applicationelement will wear off more rapidly and will have to be replaced morerapidly because the formed bead cannot be used for the applicationprocess or coating process. This increases the costs in the applicationor coating process. A further drawback is that the geometry of the layerapplied by the application element (application bead) is not uniform, sothat the application process (application coating or applicationfriction welding) cannot be performed optimally.

It is known from GB 1,053,148 A that in friction welding a form elementis used for forming the developed weld seam. The formation of a bead isthereby not prevented; rather, the weld seam is formed.

The invention provides a friction application device which, while beingof a simple structure and producible in a simple way at low costs,avoids the drawbacks of the prior art and permits a precise materialapplication.

SUMMARY OF THE INVENTION

The invention provides, in one aspect, a friction application deviceincluding an application element which defines a rotational axis andwhich is movable by a moving device on a surface of a workpiece and in arelative movement with respect to the surface of the workpiece. Thedevice also includes at least one supporting tool that is non-coaxialwith the rotational axis and having an arcuate outer periphery in directcontact with the application element.

The invention provides, in another aspect, a friction application deviceincluding an application element which is movable by a moving device ona surface of a workpiece and in a relative movement with respect to thesurface of the workpiece. The device also includes a first supportingtool and a second supporting tool, which form a gap therebetween inwhich the application element is arranged. Each of the first and secondsupporting tools has an arcuate outer periphery in direct contact withthe application element.

According to the invention it is thus provided that by means of thedevice according to the invention the application element which ismovable by means of a moving device on a surface of a workpiece andwhich for the purpose of applying material can be brought into arelative movement (turning, rotation, or the like) is supported in itscontact region with the surface of the workpiece by at least onesupporting tool which prevents bead formation. According to theinvention the contact region or the free end portion of the applicationelement is thereby supported laterally, so that only the contact surfaceon the face side (in the case of a cylindrical application element whichis rotatable about its longitudinal axis) or the circumferential surface(in the case of a disc-shaped application element) is in contact withthe surface of the workpiece while the adjoining sides of theapplication element are supported by the at least one supporting tool.Bead formation is thereby prevented because the softened and plasticizedapplication element cannot deform laterally in an undesired manner. Beadformation can thus not occur.

In a particularly advantageous development of the invention it isprovided that the supporting tool is arranged on the surface of theworkpiece. As an alternative thereto, the at least one supporting tooltogether with the application element is movable along the surface ofthe workpiece, so that the supporting tool is not supported on theworkpiece, but separately on a moving element of the applicationelement.

In a particularly advantageous configuration of the invention, it isprovided that the supporting tool is configured to be bar-shaped,roll-shaped, in the form of tapered rollers, or band-shaped. Dependingon the geometry of the supporting tool, two or more supporting tools ofsuch types may be provided. These may roll either on the surface of theapplication element, as is the case with roll-shaped or taperedsupporting tools, they may also be in a slide movement, as is realizedin the case of bar-shaped supporting tools, or they may be configured inthe form of surrounding bands.

It is particularly advantageous when the supporting tool is supported ona carrier device. In a development of the invention it may here beadvantageous when the supporting tool is provided or coupled by means ofat least one drive device to perform a relative movement with respect tothe surface of the application element.

When several supporting tools are used, it may particularly be ofadvantage when these are arranged in a position-variable manner. Forinstance, it is particularly advantageous when the supporting toolpermits a relative movement with respect to the surface of the workpieceso as to ensure upon application of a plurality of application webs thatthe respective supporting tool abuts on the surface of the workpiece andcan thereby support the foremost end portion of the application element.

In a development of the invention it is also possible that the carrierdevice on which the supporting tool(s) is (are) arranged is providedwith a heating device so as to heat the application element in addition.It may also be advantageous when the supporting tool is made from aheat-insulating or poorly heat-conducting material so as to avoid, dueto its contact with the application element, the withdrawal of heattherefrom. In an alternative configuration of the invention, it is alsopossible to provide the supporting tool itself with a heating device forheating the application element.

The friction application device according to the invention may beconfigured as a friction coating device or also as a friction weldingdevice.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention shall now be described with reference to embodiments incombination with the drawing, in which:

FIG. 1 is a simplified sectional view of an application elementaccording to the invention with bead formation;

FIG. 2 is a sectional view, by analogy with FIG. 1, of a furtherembodiment of an application element with bead formation;

FIG. 3 is a perspective view of a first embodiment of a frictionapplication device according to the invention with supporting elementsin the form of bars;

FIG. 4 is a perspective partial bottom view of the embodiment accordingto FIG. 3;

FIGS. 5 and 6 are views, by analogy with FIGS. 3 and 4, of a furtherembodiment with band-shaped supporting tools;

FIGS. 7 and 8 are views, by analogy with FIGS. 3 and 4, of a furtherembodiment with roll-shaped supporting tools;

FIGS. 9 and 10 are views, by analogy with FIGS. 3 and 4, of a furtherembodiment with cone-shaped or tapered supporting tools, and

FIG. 11 is a perspective view of a further embodiment of a frictionapplication device according to the invention with an applicationelement according to FIG. 2.

DETAILED DESCRIPTION

FIG. 1 is a simplified sectional view of an application element 1 of theinvention, which is configured in the form of a rod and is rotatableabout its rotational axis 6. The free end portion of the applicationelement 1 has a bead 5 which is due to deformation of the applicationelement 1 when said element is pressed with a force along the rotationalaxis 6 against a workpiece surface (not shown) so as to apply material.

By analogy, FIG. 2 shows a disc-shaped application element 1 with a bead5 on the outer circumferential surface, which is also in contact with asurface of a workpiece upon rotation about the rotational axis 6.

FIGS. 3 and 4 are each a perspective view of an embodiment of a frictionapplication device according to the invention. Said device comprises aframe 7 with a table 8 which has positioned thereon a holder 9 on whicha workpiece 2 is arranged. A support 12 which is only shownschematically and supports a slide 11 via suitable movement paths isformed on the frame 7. A turning spindle 10 on which a rod-shapedapplication element 1 is supported is arranged on the slide 11 (alsoonly schematically shown). With the help of the turning spindle 10 theapplication element 1 is put into rotation to apply material by way of afriction contact with the surface of the workpiece 2. Hence, a materialweb can be applied to the workpiece 2 by way of a suitable movement ofthe slide 11 and/or of the support 12. The turning spindle 10 and/or theslide 11 are movable in vertical direction to track or reposition theapplication element 1 so as to implement the material application inthis way.

In a schematic illustration, FIGS. 3 and 4 show a carrier device 4 whichis also movable relative to the workpiece 2. In the illustratedembodiment, the carrier device 4 is plate-shaped; on its upper side, itcarries a plurality of heating elements 13 which are also shown onlyschematically and heat the application element 1, for instance, byradiation heat.

In the illustrated embodiment, the bottom side of the carrier device 4has arranged thereon two bar-shaped supporting tools 3 which form a gap14 or have a mutual spacing in which the application element 1 isarranged in an accurately fitting manner. The two bar-shaped supportingtools thereby abut in the form of rails on the application element 1,which is rotating about its rotational axis 6.

According to the invention it is also possible to fix the rail-likesupporting tools, as an alternative to the illustrated variant, also tothe workpiece 2 and thus not, as shown in FIGS. 3 and 4, to move themtogether with the application element. The rail-shaped supporting toolsmay have a rectangular cross-section, but it is also possible to bevelthem in the contact region with the application element 1 so as tocounteract the formation of a bead more efficiently.

FIGS. 5 and 6 show a further embodiment, wherein, like in the precedingand the subsequent figures, like parts are provided with like referencenumerals.

In the embodiment shown in FIGS. 5 and 6, the supporting tools areconfigured as surrounding boundary bands which are guided by means of adrive (not shown) around a support body 15. Owing to the movement of theband-shaped supporting tools 3 no relative movement occurs between thesupporting tools 3 and the application element 1, so that theband-shaped supporting tools 3 carry out a rolling movement and therebyprevent bead formation.

In the embodiment of FIGS. 7 and 8, three supporting tools 3 areprovided that are configured in the form of rolls. The supporting tools3 enclose the free end portion of the application element 1 and supportthe same, so that no bead is formed and/or that, as in the case of thepreviously described embodiments, the application element immediatelyresumes its shape upon bead formation.

In this embodiment, the supporting tools 3 are also rolling on thesurface of the application element 1 in a way similar to the embodimentdescribed in FIGS. 5 and 6, so that there is no relative movement, andchip formation caused by a shearing off of the material of theapplication element can thus not take place either.

FIGS. 9 and 10 show a further embodiment in which, by analogy with theembodiment of FIGS. 7 and 8, three supporting tools 3 are provided thatare cone-shaped or tapered and are inclined in their axes relative tothe rotational axis 6 of the application element 1. In this embodiment,it is possible in a particularly efficient manner to avoid beadformation of the end portion of the application element 1, with thesupporting tools 3 being not in contact or only in slight contact withthe surface of the workpiece 2.

FIG. 11 shows a further embodiment of a friction application deviceaccording to the invention, wherein like parts are also provided withlike reference numerals as in the preceding embodiments.

As shown in FIG. 2, the application element 1 is disc-shaped and isrotating about its rotational axis 6.

As shown in FIG. 11, a frame 7 has formed thereon a table 8 whichcarries a holder 9 on which a workpiece 2 is arranged. Said workpiece isfriction-coated by contact with the rotating application element 1. Forthis purpose a shaft 16 which carries the application element 1 issupported on a turning spindle 10 which is supported in a slide 11. Theslide 11 also comprises a drive device (not shown), as is also the casewith the above-described embodiments. The slide 11 together with acounter bearing 17 supporting the shaft 16 is movable relative to theworkpiece 2, either by movement of the holder 9 or by movement of theslide 11 and the counter bearing 17.

Roll-shaped supporting tools 3 are supported, for instance by means ofbearing elements 18, on a bridge 19 which connects the slide 11 and thecounter bearing 17. The supporting tools 3 roll on the respectivesurface of the application element and prevent the formation of a beador the shaping of a bead portion.

Various features of the invention are set forth in the following claims.

1. A friction application device comprising: an application elementwhich defines a rotational axis and which is movable by a moving deviceon a surface of a workpiece and in a relative movement with respect tothe surface of the workpiece; and at least one supporting tool that isnon-coaxial with the rotational axis and having an arcuate outerperiphery in direct contact with the application element.
 2. Thefriction application device according to claim 1, wherein the rotationalaxis is a first rotational axis, wherein the supporting tool rotatesabout a second rotational axis, wherein and the first rotational axis isperpendicular to the second rotational axis.
 3. The friction applicationdevice according to claim 1, wherein the supporting tool together withthe application element is movable along the surface of the workpiece.4. The friction application device according to claim 1, furthercomprising: a shaft upon which the application element is supported andco-rotatable therewith; a spindle coupled to a first end of the shaftfor imparting rotation to the shaft; and a counter bearing rotatablysupporting a second end of the shaft.
 5. The friction application deviceaccording to claim 4, further comprising a slide containing a drivedevice for imparting rotation to the spindle, wherein the applicationelement is positioned between the slide and the counter bearing in adirection along the rotational axis.
 6. The friction application deviceaccording to claim 5, further comprising a bridge interconnecting theslide and the counter bearing, wherein the supporting tool is supportedon the bridge.
 7. The friction application device according to claim 6,wherein the application element is located between the bridge and theworkpiece in a direction transverse to the rotational axis.
 8. Thefriction application device according to claim 6, further comprising abearing element mounted to a top surface of the bridge from which thesupporting tool is rotatably supported, wherein the supporting tool isarranged adjacent a bottom surface of the bridge.
 9. The frictionapplication device according to claim 1, wherein the supporting tool isroll-shaped.
 10. The friction application device according to claim 1,wherein the application element is configured as a disk having anarcuate outer peripheral surface, a first side adjacent the arcuateouter peripheral surface and transverse to the rotational axis, and asecond side adjacent the arcuate outer peripheral surface and parallelwith the first side, and wherein the arcuate outer periphery of thesupporting tool is in direct contact with one of the first side or thesecond side of the application element.
 11. The friction applicationdevice according to claim 1, wherein the friction application device isconfigured as a friction coating device or as a friction welding device.12. The friction application device according to claim 1, wherein thesupporting tool is made from a heat-insulating material or a material ofpoor heat conductivity.
 13. A friction application device comprising: anapplication element which is movable by a moving device on a surface ofa workpiece and in a relative movement with respect to the surface ofthe workpiece; and a first supporting tool and a second supporting tool,which form a gap therebetween in which the application element isarranged, each include an arcuate outer periphery in direct contact withthe application element.
 14. The friction application device accordingto claim 13, wherein the application element rotates about a firstrotational axis, and wherein each of the first and second supportingtools rotates about a second rotational axis perpendicular to the firstrotational axis.
 15. The friction application device according to claim13, wherein the first supporting tool, the second supporting tool, andthe application element are movable together along the surface of theworkpiece.
 16. The friction application device according to claim 13,further comprising: a shaft upon which the application element issupported and co-rotatable therewith; a spindle coupled to a first endof the shaft for imparting rotation to the shaft; and a counter bearingrotatably supporting a second end of the shaft.
 17. The frictionapplication device according to claim 16, further comprising a slidecontaining a drive device for imparting rotation to the spindle, whereinthe application element is positioned between the slide and the counterbearing in a direction along a rotational axis of the shaft and theapplication element.
 18. The friction application device according toclaim 17, further comprising a bridge interconnecting the slide and thecounter bearing, wherein the first and second supporting tools aresupported on the bridge.
 19. The friction application device accordingto claim 13, wherein the application element is configured as a diskhaving an arcuate outer peripheral surface, a first side adjacent thearcuate outer peripheral surface and transverse to a rotational axis ofthe application element, and a second side adjacent the arcuate outerperipheral surface and parallel with the first side, and wherein thearcuate outer peripheries of the first and second supporting tools,respectively, are in direct contact with the first and second sides ofthe application element.
 20. The friction application device accordingto claim 13, wherein the first and second supporting tools are made froma heat-insulating material or a material of poor heat conductivity.